<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>自定义遍历数据</title>
</head>
<body>
    <script>
        //声明一个对象
        const banji = {
            name: '终极一班',
            stus: [
                'xiaoming',
                'xiaoning',
                'xiaotian',
                'knight'
            ],
            [Symbol.iterator]() {
                //索引遍历
                let index = 0;
                //定义一个保存this变量的this
                let that = this;

                return {
                    next : function() {
                        if(index < that.stus.length) {
                            //done为false，迭代程序不停
                            const result = {value: that.stus[index], done: false};
                            //下标自增
                            index++;
                            //返回结果
                            return result;
                        } else {
                            return {value: undefined, done: true};
                        }
                    }
                };
            }
        }
        
        //遍历这个对象
        for(let v of banji) {
            console.log(v);
        }
    </script>
</body>
</html>